1. Field of the Invention
The present invention relates to an assembly of connection flange to a wheel rim and a brake disc.
In particular, the present invention relates to an assembly of connection flange to a wheel rim and brake disc, for example for commercial vehicles.
2. Description of the Prior Art
As it is known, the commercial vehicles have support members of the wheel rims, or hubs, comprising bearings that are sufficiently robust to be able to support high transport loads.
Typically, these hubs are connected to axles or traction axles, or motors, which allow a free rotation of the bearing, and therefore of the wheel rim connected thereto, or the transmission of a torque.
In the case that these hubs are used for commercial vehicles, the housed bearings have to support even very high loads. Although the friction between the axle and the hub is particularly limited, by virtue of the use, for example, of volving bearings, for example roll bearings, in the case that the action to be transmitted through the bearing is particularly high, a considerable heating of the bearing and of all the components contiguous thereto is created. This heating has to be suitably dissipated in order not to compromise the proper operation of the bearings housed in the hub and therefore, possibly, of the disc for disc brake that is connected thereto.
Also the braking system determines, when it is actuated, a particular heat production. In fact, the braking action of the vehicle converts, by virtue of the friction between its components, the kinetic energy into thermal energy. The fact that the disc for disc brake is connected to the support hub of the wheel rim, determines, in the case of repeated and intense braking actions, for example in the case that the vehicle has to go downhill of a mountain pass, a great increase in the temperature of the disc for disc brake and also of its portions connected to the hub, and in particular to the bearing, thus causing an even considerable heating of the bearing housed therein. In the case that the brake disc is not suitably cooled, it is possible to compromise the proper operation not only of the disc, but also of the bearing.
Therefore, the need of devising and providing a solution that allows a suitable cooling not only of the disc for disc brake, but particularly of the interface between the disc for disc brake and the bearing received therein is particularly felt.
Solutions that have means for the passage of cooling air through the wheel rim are known, in particular the connection flange between the hub and the wheel rim.
For example, the document EP 1 162 385 by SAF Holland GmbH has an assembling apparatus for a wheel that comprises a hub wheel and a flange having a wheel assembling portion to be connected to the wheel, and having a hub assembling portion to be connected to a hub wheel. Ventilation passages are provided for between the wheel assembling portion and the hub assembling portion.
This solution has considerable drawbacks, because it allows the passage of cooling air through openings of the hub and rim connection flange by evacuating the heat developed by the braking surfaces, particularly the braking surface facing the rim, but in no way it can concur to the cooling of the heat developed by the bearing, or transmitted to the bearing, through the drum from the brake disc.
Other solutions of hub and rim connection flange openings are known from the documents U.S. Pat. No. 3,952,820 by SKF Nova A.B. and from the document U.S. Pat. No. 5,921,633 by Fag Automobiltechnik AG, which however have the drawbacks of the solution EP 1 162 385.
Therefore, it is particularly felt the need of manufacturing a disc flange assembly for disc brake that allows a suitable cooling not only of the disc, but also of the bearing, and in particular that allows a suitable evacuation of the cooling fluid.